Vacuum tube device



' Oct. 13, 1936. A \NILSON 2,057,508

VACUUM TUBE DEVI CE Original Filed Aug. 25, 1925 INVENTOR WITNESSES:

Patented Get. 13, 1936 UNH'E'ED STATES PATENT OFFIQE VACUUM TUBE DEVICE Application August 25, 1923, Serial No. 659,250 Renewed March 19, 1930 1 Claim.

My invention relates to thermionic devices and more especially, to the construction and operation of such devices.

In its broadest aspect, an object of my invention is to provide a device of the character described, which is particularly. designed for use as a high-capacity power tube in wireless transmission systems.

More specifically, another object of my invention is to provide a power tube which is characterized by its simplicity of design, ruggedness of construction and high operating efficiency.

A further object of my invention is to provide a high-capacity power tube embodying such construction as to provide for the ready removal of the energy dissipated at the operating elements thereof.

In a practical embodiment of my invention, the foregoing desired results are obtained by providing an elongated double-walled tubular member, the inner and outer walls of which function respectively as a control electrode and as an anode element. A cathode is positioned in the annular chamber formed by said walls and is supported from opposite ends of the tubular member. The heat energy dissipated in the tube during normal operation may be carried away by causing a circulation of air, oil or other cooling medium around the inner and the outer walls of the device, all as explained more fully hereinafter.

Other objects and applications of my invention, as well as details of construction and operation, whereby my invention may be practiced, will be apparent more fully hereinafter when taken in connection with the accompanying claim, description and drawing, wherein Figure 1 is a view, partially diagrammatic and partially in longitudinal section, of circuits and apparatus embodying my invention, and

Fig. 2 is a section on line IIII of Fig. 1.

In the illustrated embodiment of my invention shown in the drawing, I provide a power-tube 2 and 3 designed to serve as electrodes comprising a pair of concentrically positioned metallic cylinders, the difference in diameters thereof being determined by the desired relative spacing between said metallic elements. Although I have spoken of these elements as cylindrical and the space between them as annular it is to be understood that other shapes may be used and that the inner element need not be concentric with the! outer one. The cylinders 2 and 3, which may be made of any non-porous metallic substance, as for instance, copper, are insulatingly spaced and supported and the annular space defined by the walls of the two cylinders 2 and 3 is formed into a closed chamber 4 by mounting the opposite ends thereof in rings 5 and 6, respectively, of some insulating, non-porous material, as quartz 5 or glass.

The end portions of the concentrically disposed cylinders 2 and 3, which are embedded in the rings 5 and 6, are sealed in any well-known manner to permit maintaining the annular chamber 4 in an evacuated condition, the evacuation being effected in any well-known manner. The larger cylinder 2 which preferably serves as an anode by reason of its greater heat dissipating surface, may be connected to external circuits 15 (not shown) by means of a conductor 1 extending from a point on the outer surface thereof. The remaining cylindrical member 3 may be caused to function as a control electrode by connecting the same through a conductor 8 which extends from the exposed surface thereof, to external circuits (not shown).

A pair of conducting annular members 9 and II are positioned in the evacuated annular chamber 4 immediately adjacent to the opposite end portions thereof and are supported by a plurality of carrier rods 12 and !3, respectively. A plurality of filament elements 54 may be positioned in the space between said carrier rings 9 and. H and supported thereby in such manner that the several filaments l4 constitute a cylindrical surface which is positioned intermediate the containing-wall electrodes 2 and 3. The filament It may be connected with external terminal conductors l5 and I6 by extending one or more of the carrier rods l2 and 13 through the sealing rings 5 and 6, respectively.

The energy which is dissipated in the tube; device I during normal operation thereof is carried away by circulating air or other cooling medium as oil around past the exposed portions of the tube, as previously stated. In the drawing, one method for accomplishing this is shown wherein the power tube i is immersed in a receptable l1 containing oil l8, circulation being provided through inlet and outlet passages I9 and 2|, respectively, in the general direction indicated by the arrows.

While I have shown only a specific embodiment of my invention for the purpose of describing the same and illustrating its principles of construction and operation, it is apparent that various changes and modifications may be made therein without departing from the spirit and scope of my invention. I desire, therefore, that 55 only such limitations shall be imposed thereon as are indicated by the appended claim or as are demanded in the prior art.

I claim as my invention:

A vacuum tube of annular form comprising a metallic outer wall and a metallic inner wall constituting electrodes of the tube, non-metallic end portions, each sealed to both of said walls, two pluralities of standards, one plurality '10. mounted in each of said end portions, each 

